1. The Field of the Invention
The present invention relates generally to optoelectronic devices. More specifically, the present invention relates to optoelectronic devices that use microcode to perform end-of life and related calculations for a light source, such as a laser diode included in an optical transmitter.
2. The Related Technology
Computing and networking technology have transformed our world. As the amount of information communicated over networks has increased, high speed transmission has become ever more critical. Many high speed data transmission networks rely on optical transceivers and similar devices for facilitating transmission and reception of digital data embodied in the form of optical signals over optical fibers. Optical networks are thus found in a wide variety of high speed applications ranging from modest Local Area Networks (“LANs”) to backbones that define a large portion of the infrastructure of the Internet.
Typically, data transmission in such networks is implemented by way of an optical transmitter (also referred to as an “optoelectronic transducer”), such as a laser or Light Emitting Diode (“LED”). The optoelectronic transducer emits light when current is passed through it, the intensity of the emitted light being a function of the magnitude of the current. Data reception is generally implemented by way of an optical receiver (also referred to as an optoelectronic transducer), an example of which is a photodiode. The optoelectronic transducer receives light and generates a current, the magnitude of the generated current being a function of the intensity of the received light.
Various other components are also employed by the optical transceiver to aid in the control of the optical transmit and receive components, as well as the processing of various data and other signals. For example, such optical transceivers typically include a driver (e.g., referred to as a “laser driver” when used to drive a laser signal) configured to control the operation of the optical transmitter in response to various control inputs. The optical transceiver also generally includes an amplifier (e.g., often referred to as a “post-amplifier”) configured to amplify the channel-attenuated received signal prior to further processing. A controller circuit (hereinafter referred to as the “controller”) controls the operation of the laser driver and post-amplifier.
During operation of the transceiver, the operation and environment of the transceiver can affect the life span of the laser. Additionally, a host system or other user of the transceiver typically desires to know the remaining life span of the laser. Conventionally, the “end of life” of the laser was estimated by providing the host system with “beginning of life” characteristics of the laser, which were determined and stored in the transceiver module at the time of manufacture. The host system would then be required to measure and/or calibrate certain parameters such as laser current, transmit power and receive power. The beginning of life data included a set point and coefficients for these parameters. Using analog parameter measurements and the beginning of life data, an end of life calculation could be performed. However, this required the host system to exert a significant amount of effort to gather and process data. Further, in some cases, some host systems do not have the capacity to measure data, calibrate data, and/or perform this calculation.
Further, conventional methods do not provide for the most accurate estimation of end of life of a laser because they have not accounted for additional factors that affect the life span of the laser. However, these additional factors are not easily obtained by the user. In addition, the extent to which each parameter affects the end of life of the laser can change as the laser ages, according to the actual operation of the laser. Conventional methods of calculating the end of life of a laser are unable to account for these variations.
Thus, conventional systems and methods for estimating the end of life of a laser can require a significant amount of effort, thereby increasing the cost not only of the optical transceiver itself, but its operation as well. Therefore, what would be desired is an optical transceiver that provides an estimate of end of life of the laser without requiring excessive participation by the host system in which the transceiver is located.